BoilerFaultCodes 2b High
Boiler Fault Code 2b
Also written as 2B — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 2b appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is struggling to circulate water, which is causing a loud noise because the internal pump has stopped working. (As reported on Chaffoteaux Celtic 2 24 Rsc)
Pick your boiler brand for the 2b fix
Source
Information for the 2b fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026